1. Field of the Invention
The present invention relates to a mattress and more particularly to such a combination mattress wherein the user can self adjust the resilience of the combination mattress.
2. Description of the Related Art
A conventional mattress comprises two pads, a spring shelf mounted between the two pads, and a cover mounted around the outer periphery of the two pads and the spring shelf. When a user lies on the mattress, the portion of the mattress contacting the human body is deformed with the profile of the human body, then the spring shelf provides enough support force, so that the user has a comfortable sensation when lying on the mattress.
However, the resilience of the mattress is controlled by the elasticity of the spring shelf, the spring shelf can only provides a single elastic force to support the human body. Thus, if the user wishes to change the resilience of the mattress according to the requirement of the human body, he has to buy another mattress which resilience conforms to the requirement of the human body, thereby increasing the user's economic burden, and causing disturbance in use.